Fermion or Boson Dark Matter?

We measure properties of dark matter in four well motivated scenarios: fermions with ultra-relativistic thermal equilibrium (URTE), bosons with URTE, fermions with non-relativistic thermal equilibrium (NRTE), and bosons with NRTE. We attempt to discriminate between these four scenarios with studies of spiral galaxy rotation curves, and galaxy stellar mass distributions. The measurements show evidence for boson dark matter with a significance of 3.5σ, and obtain no significant discrimination between URTE and NRTE.

An Analytical Solution in the Complex Plane for the Luminosity Distance in Flat Cosmology

We present an analytical solution for the luminosity distance in spatially flat cosmology with pressureless matter and the cosmological constant. The complex analytical solution is made of a real part and a negligible imaginary part. The real part of the luminosity distance allows finding the two parameters H0 and ΩM . A simple expression for the distance modulus for SNs of type Ia is reported in the framework of the mini-max approximation.

Sparse Formulae for the Distance Modulus in Cosmology

We review the distance modulus in twelve different cosmologies: the ΛCDM model, the wCDM model, the Cardassian model, the flat case, the øCDM cosmology, the Einstein—De Sitter model, the modified Einstein—De Sitter model, the simple GR model, the flat expanding model, the Milne model, the plasma model and the modified tired light model. The above distance moduli are processed for three different compilations of supernovae and a supernovae + GRBs compilation: Union 2.1, JLA, the Pantheon and Union 2.1 + 59 GRBs. For each of the 48 analysed cases we report the relative cosmological parameters, the chi-square, the reduced chi-square, the AIC and the Q parameter. The angular distance as function of the redshift for five cosmologies is reported in the framework of the minimax approximation.

DESI Legacy Imaging Surveys Data Release 9:Cosmological constraints from galaxy clustering and weak lensing using the minimal bias model

We present a tentative constraint on cosmological parameters Ω_(m) and σ_(8) from a joint analysis of galaxy clustering and galaxygalaxy lensing from DESI Legacy Imaging Surveys Data Release 9(DR9),covering approximately 10000 square degrees and spanning the redshift range of 0.1 to 0.9.To study the dependence of cosmological parameters on lens redshift,we divide lens galaxies into seven approximately volume-limited samples,each with an equal width in photometric redshift.To retrieve the intrinsic projected correlation function w_(p)(r_(p))from the lens samples,we employ a novel method to account for redshift uncertainties.Additionally,we measured the galaxy-galaxy lensing signal ΔΣ(r_(p))for each lens sample,using source galaxies selected from the shear catalog by applying our Fourier Quad pipeline to DR9 images.We model these observables within the flatΛCDM framework,employing the minimal bias model.To ensure the reliability of the minimal bias model,we apply conservative scale cuts:r_(p)>8 and 12 h^(-1)Mpc,for w_(p)(r_(p))and ΔΣ(r_(p)),respectively.Our findings suggest a mild tendency that S_(8)=σ_(8)√Ω_(m)/0.3increases with lens redshift,although this trend is only marginally significant.When we combine low redshift samples,the value of S8is determined to be 0.84±0.02,consistent with the Planck results but significantly higher than the 3×2 pt analysis by 2-5σ.Despite the fact that further refinements in measurements and modeling could improve the accuracy of our results,the consistency with standard values demonstrates the potential of our method for more precise and accurate cosmology in the future.

Elucidating galaxy assembly bias in SDSS

We investigate the level of galaxy assembly bias in the Sloan Digital Sky Survey (SDSS) main galaxy sample using ELUCID,a state-of-the-art constrained simulation that accurately reconstructed the initial density perturbations within the SDSS volume.On top of the ELUCID haloes,we develop an extended HOD model that includes the assembly bias of central and satellite galaxies,parameterized as Q_(cen)and Q_(sat),respectively,to predict a suite of one-and two-point observables.In particular,our fiducial constraint employs the probability distribution of the galaxy number counts measured on 8 h^(-1)Mpc scales N_8^(g) and the projected cross-correlation functions of quintiles of galaxies selected by N_(8)^(g) with our entire galaxy sample.We perform extensive tests of the efficacy of our method by fitting the same observables to mock data using both constrained and non-constrained simulations.We discover that in many cases the level of cosmic variance between the two simulations can produce biased constraints that lead to an erroneous detection of galaxy assembly bias if the non-constrained simulation is used.When applying our method to the SDSS data,the ELUCID reconstruction effectively removes an otherwise strong degeneracy between cosmic variance and galaxy assembly bias in SDSS,enabling us to derive an accurate and stringent constraint on the latter.Our fiducial ELUCID constraint,for galaxies above a stellar mass threshold M_(*)=10^(10.2)h^(-2)M_(⊙),is Q_(cen)=-0.09±0.05 and Q_(sat)=0.09±0.10,indicating no evidence for a significant (>2σ) galaxy assembly bias in the local Universe probed by SDSS.Finally,our method provides a promising path to the robust modelling of the galaxy-halo connection within future surveys like DESI and PFS.

Hidden periodicity in Stripe 82 with Saraswati supercluster—a fractal analysis

The manuscript attempts to explore the periodicity in the distribution of galaxies in the recently reported Saraswati supercluster and the Stripe 82 region containing it as an example.The report of 120 Mpc periodicity in the Abell galaxy clusters by power spectrum analysis is the motivation behind the study.The power spectral analysis across the central part of the Stripe 82 region shows a periodic variation of 3.09°or 71 Mpc in fractal dimension whereas an average angular periodicity of 3.45°or 94 Mpc is observed across the Stripe 82 region.This refers to the periodicity of complexity or cluster density of galaxy distribution.The texture of the distribution pattern understood through lacunarity analysis indicates a near symmetric distribution.Fractal dimensions like box-counting dimension,information dimension and correlation dimension are also found through multifractal analysis.While the information dimension tells about the distribution density of galactic points,the correlation dimension details the distribution of galaxies in the neighbourhood.